Canon EOS Rebel T6s Telephoto Lens Kit 业主指南

下载
页码 680
f
: Changing the Depth of Field
164
To obtain a correct flash exposure, the flash output will be set 
automatically to match the set aperture (autoflash exposure). The 
shutter speed will be set automatically between 1/200 sec. - 30 sec. to 
suit the scene’s brightness.
In low light, the main subject is exposed with the auto flash metering, 
and the background is exposed with a slow shutter speed set 
automatically. Both the subject and background look properly exposed 
with a touch of atmosphere (automatic slow-speed flash sync). If you 
are handholding the camera, keep it steady to prevent camera shake. 
Using a tripod is recommended.
To prevent a slow shutter speed, under [z1: Flash control], set 
[Flash sync. speed in Av mode] to [1/200-1/60sec. auto] or [1/200 
sec. (fixed)
] (p.184).
The aperture opening (diaphragm) changes only at the moment when 
the picture is taken. Otherwise, the aperture remains fully open. 
Therefore, when you look at the scene through the viewfinder or on the 
LCD monitor, the depth of field will look narrow.
Press the depth-of-field preview button 
to stop down the lens to the current 
aperture setting, and check the depth of 
field (range of acceptable focus).
D
 Using the Built-in Flash
Depth-of-Field PreviewK
While looking at the Live View image (p.202) and holding down the depth-of-
field preview button, you can see how the range of acceptable focus will 
change as you adjust the aperture.